1. Field of the Invention
The present invention relates to flashlights in general, and in particular to an improved assembly for a disposable planar flashlight.
2. Description of Related Art
Like much of the technology in today's society, flashlight technology has become lighter, thinner, smaller, and more convenient due in part to the advances in the components which make up the flashlight. For example, the availability of batteries such as the thin 6 volt dry cell battery made by Polaroid Corporation of Cambridge, Mass., has reduced the size requirements of the flashlight itself to that slightly bigger than a credit card. One example of a planar lightweight flashlight is described in U.S. patent application Ser. No. 08/369,719, authored by this inventor and incorporated by reference herein. Other improvements include the advances, in smaller, more durable light bulbs which can produce more light than heretofore with the earlier light bulbs of the art.
The battery suggested by the above cited flashlight has the dimensions of an ordinary playing card and two terminals on a rear surface. The battery itself has a slight rectangular bulge projecting from the forward surface where the dry cell is located. The light bulbs are connected to the terminals using insulated wires, and tape may be used to secure the wires and the switch to the battery. The light bulbs are enclosed in the window area formed by the transparent sheet, but the whole assembly lacks a rigid structure to define the locations of each component.
Difficulties of the design of the disposable "credit card" flashlight art concern the assembly of the flashlight and its durability. Previous attempts to secure the contacts and the switch to the battery have involved adhesives and tape, which are unreliable and subject to temperature changes. Furthermore, assembly of the flashlights due to the taping of wires was too labor intensive for a product designed to be disposable. Another drawback is the lack of a protective element for the pressure sensitive on-off switch, allowing the switch to be inadvertently activated when stored in tight places such as a wallet or purse. This inadvertent activation could lead to the flashlight's premature expiration, which in turn leads to customer dissatisfaction. The lack of a protective element also concerns the fragile nature of the small light bulbs, which may be broken or crushed if care is not exercised. The design further lacks a rigid structure, allowing the wires and light bulbs to be positioned by tape or other temporary adhesive measures. Finally, the contacts may become misaligned or disconnected since the tape or adhesive does not provide any support for the elements.